Knowing the sign of the work done on an object is a crucial element to understanding work. Positive work indicates that an object has been acted on by a force that tranfers energy to the object, thereby increasing the object's energy. Negative work indicates that an object has been acted on by a force that has reduced the energy of the object. The next few questions will ask you to determine the sign of the work done by the various forces acting on a box that is being pushed across a rough floor. As illustrated in the figure (Figure 1) , the box is being acted on by a normal force , the force due to gravity , the force of kinetic friction , and the pushing force . The displacement of the box is .Which of the following statements accurately describes the sign of the work done on the box by the force of the push? Which of the following statements accurately describes the sign of the work done on the box by the force of the push? positive negative zero Which of the following statements accurately decribes the sign of the work done on the box by the normal force? positive negative zero Which of the following statements accurately decribes the sign of the work done on the box by the force of kinetic friction? positive negative zero Which of the following statements accurately decribes the sign of the work done on the box by the force of gravity? positive negative zero